In June, Facebook flew a massive drone with a wingspan surpassing that of a Boeing 737 over the Arizona desert. The unmanned, autonomous aircraft stayed aloft for more than 90 minutes before it crashed upon landing.
It was the first flight of Facebook’s solar-powered Aquila drone, which the social media company had been working on for two years. Facebook hopes to one day use the drone to beam internet over areas that lack reliable connectivity.
“The aircraft was substantially damaged,” according to a report issued Friday from the National Transportation Safety Board.
The failure was likely due to a strong wind gust that lifted the drone above its flightpath right before landing, causing the autopilot controls to lower the nose and speed up as it came down.
The turbulent landing caused substantial damage to the drone’s right wing, but no one was injured, nor was there any damage on the ground, the report said.
Facebook’s drone was only supposed to fly for 30 minutes in its first test run. But as the flight seemed to be going well, the engineers decided to keep the drone airborne three times longer, for a total of 96 minutes, Facebook CEO Mark Zuckerberg boasted in a blog post in July. The flight took place in the early morning, just as the sun began to rise.
During the extra hour of flight, the sun heated the air. Yael Maguire, who heads Facebook’s Connectivity Lab, told TechCrunch that in the last four seconds of flight, his team noted thermal changes and unexpected wind that they hadn’t encountered in simulations.
Facebook reported the landing failure to the National Transportation Safety Board right away, according to a Friday blog post, but the company was prohibited from sharing details of the crash until the regulators were done writing their report.
The social media company said that it is already working on an updated version of the Aquila drone, with a new kind of brake system that will help the autopilot land more smoothly.
Eventually, Facebook hopes to fly its drone for 60 to 90 days at a time, since it’s solar-powered and doesn’t need to refuel.
Aquila isn’t Facebook’s first project aimed at providing internet connectivity to areas that lack reliable access. The company also runs Free Basics, a zero-rated, limited version of the internet that Facebook offers to users for free in 53 countries and municipalities around the world.
Regulators in India, however, banned Free Basics earlier this year, claiming that the service was a violation of network neutrality in that it privileged access to some websites over others.
According to the Internet.org website, which is the homepage of the Free Basics program, anyone is allowed to add their website to the platform as long as they adhere to Facebook’s guidelines to “optimize for performance on older phones and slower network connections.” But Facebook still acts as the gatekeeper.
When Zuckerberg first shared his ambitions for Aquila, he said it was part of the same Internet.org iniative.
Watch a video of Facebook’s Aquila drone test flight from June:
This article originally appeared on Recode.net.